PSR 1957 + 20

This paper reports on polarization data at 430 MHz collected at the 305-m telescope at Arecibo. Left and right circularly polarized signals were coherently dedispersed to remove the smearing of the pulse profile caused by propagation through the ionized interstellar medium. The dedispersed signals were detected and cross multiplied in a newly constructed multiplying polarimeter and then they were sampled and synchronously averaged with the pulse period. To verify system integrity, the authors alternately observed PSR 1957 + 20 and the millisecond pulsar 1937 + 21, for which our system produced fractional polarization results in good agreement with previously published data. The average polarization profile for 1957 + 20 is presented. The authors observed only slight linear polarization, with a somewhat more substantial circular component. The authors' signal-to-noise ratio was insufficient to measure a position angle variation across the pulse profile